SAN FRANCISCO, April 27 (Reuters) - Alphabet Inc President Sergey Brin said on Friday that technology companies must take greater responsibility for the social impact of their work, his first comments following a year of heightened global awareness about misuse of digital services.

Brin delivered the message through Alphabet's annual shareholder letter, which he signed for the first time since 2014 instead of Chief Executive Larry Page.

"We’re in an era of great inspiration and possibility, but with this opportunity comes the need for tremendous thoughtfulness and responsibility as technology is deeply and irrevocably interwoven into our societies," Brin wrote after quoting from Charles Dickens’ novel "A Tale of Two Cities" about the "the best of times" and "the worst of times."

Alphabet's primary unit, Google, has become a top target in Silicon Valley for regulators, authorities and critics in advertising and media. It has drawn global scrutiny for its dominance in online search advertising, its policies around user privacy and its role in helping politically consequential misinformation spread online.

Brin did not touch on those issues, nor did he specify any actions the company would take to recognize new responsibilities.

But Brin focused on artificial intelligence, computer systems that are able to learn without humans hard-coding them. Artificial intelligence enables self-driving cars and software that can identify diseases.

Brin said that Alphabet would tread with "serious thought and research" about societal consequences such as eliminating jobs and advancing biases as the company expands use of artificial intelligence.

"While I am optimistic about the potential to bring technology to bear on the greatest problems in the world, we are on a path that we must tread with deep responsibility, care and humility," he said.

Alphabet separately announced Friday details regarding its annual shareholder meeting, which it scheduled for June 6. The company recommended shareholders reject each of the seven proposals brought by investors that call for it to provide more information around gender pay disparity, environmental impact policies, content moderation and other issues. (Reporting by Paresh Dave; Editing by Cynthia Osterman)